plz. tell me about the trends in atomic and ionic size as well as that of oxidation states in lanthanoids.
) Lanthanoids mainly exhibit +3 oxidation state. In addition, they show lower oxidation state of +2 and higher oxidation state of +4. Actinoids also exhibit +3 oxidation state. In addition, they show a wide range of higher oxidation states from +4 to +7. This is due to comparable energies of 5f, 6d and 7s orbitals in actinoids.